L&T: Lens Choices

Jul2007

Matching Presbyobes With Progressives

Progressive addition lenses (PALs) improve
the lives of countless patients who have
developed presbyopia. With their ability to
correct vision at a variety of distances and
with presbyopia a natural inevitability for
most, PALs are an attractive vision correction
option for a growing segment of the
aging population.

Today there are more PAL designs available
than ever before, giving eyecare professionals
(ECPs) more options to provide the best
vision to their presbyopic patients. Yet the
ever-expanding array of options and the wide
range of price points can easily become confusing.
Should ECPs encourage patients to
wear the newest PALs made with digital surfacing,
freeform technology and wavefront
design, or should they simply stick with the
older, established PAL designs the patient
may be used to wearing? Is a general purpose
PAL right for all situations or does the patient
also need a specialized PAL for office work,
sports or playing the piano? Should an
emerging presbyope receive the same lens
design as a more experienced presbyope?

With so many choices, it’s more important
than ever for ECPs to stay current with their
PAL knowledge to make the best recommendations
to their presbyopic patients. This
involves judgment and expertise. It’s not so
much a matter of finding the best PAL as it
is finding the best match for the wearer.

DETERMINING PATIENT NEEDS
Experienced opticians have long combined
the function of the lenses with the fashion
of the frame in a carefully chosen pair of
spectacles. Today’s ECPs can carry this concept
further, matching their presbyopes to
PALs of the most suitable design,
material and treatment.

The PAL selection process usually
begins with a discussion of the
patient’s occupational and recreational
activities and the visual tasks
that accompany them. Lifestyle
questionnaires can capture basic
information, but it’s often helpful
to probe a bit further to find out
how the patient’s visual needs
might require specific solutions that
change throughout the day. For
instance, your patient may like to
wear a fashionably small frame at
the office, but then switch to wraparound
sunglasses when they play
tennis on the weekend. In this case,
a short-corridor PAL would work
best for the office and an eightbase,
polarized PAL with optics customized
for wraps would be the
ideal second pair.

While no two patients are alike,
grouping presbyopic patients into
the following categories makes it
easier for the ECP to narrow down
the PAL selection process.

EMERGING PRESBYOPES
Emerging presbyopes are generally the ideal
PAL candidates, having no bifocal habits to
unlearn, but they may be coming to you out
of frustration with their inability to see things
up close and may be sensitive about needing
“old person” glasses.

PALs should be presented as a solution for
correcting vision for a variety of distances.
However, the wearer won’t see properly if
they misuse the PAL. While PALs have to
match the wearer, the lenses and the wearer’s
expectations need to match, too.

Most PALs offer soft designs that are great
for an emerging presbyope because these
designs are more fluid and individualized for
the wearer than earlier generation PALs. The
emerging presbyope has choices, so emphasize
that fact.

Although there may be no getting around the loss of elasticity of the crystalline lens
and the accompanying presbyopia, there are
many options to address this need, from
lightweight materials and sleek frames, to
PALs of all sizes and uses.

Don’t hesitate to recommend the best lenses,
materials and treatments, because your
customer will enjoy being offered first class
options, materials and service. You will be
most successful starting with the best option,
with a less expensive option available, should
cost remain an issue. Be prepared for curve
balls, though, since you will also run into a few
emerging presbyopes who have no idea eyeglasses
are priced like other quality items.

These will be the occasional exception to the
rule because once the benefits are made clear,
most patients will realize that PALs are a really
good value, delivering vision correction in a
variety of circumstances.

BIFOCAL AND
TRIFOCAL WEARERS
Bifocal and trifocal wearers become
potential converts to progressives as
their need for intermediate correction
increases. These patients can
benefit from PALs and can be fit in
PALs designed especially for them.
These PAL designs feature a hard
design, giving the wearer a window
like their lined lenses with a progression
of add power.

Bifocal wearers benefit from an
intermediate zone absent from their
current lens, so present PALs as an
improvement, offering benefits that
are obvious such as an absence of
lines and less image jump, as well as
less obvious benefits such as wider
range of availability in many materials
and treatments. Prescriptions of plus
power can be made thinner in PALs
than bifocals, ensuring a sleeker profile
and more secure fit in the frame.
Again, determine patient expectations
and present PALs accurately
before converting bifocal wearers. Most
PALs offer a non-adapt warranty, offering a
free exchange for bifocals if the wearer cannot
tolerate the PAL.

OTC READERS WEARERS
For millions of presbyopes, buying over-the-counter readers is the first stop on the
road to wearing PALs. Of course, OTC
readers have severe limitations such as one
standard PD and prism resulting from this,
and lower quality lens material and processing, but they may allow some presbyopes to
postpone PALs, at least for a while.

Remember, every patient who wears
OTC readers is a potential candidate for
PALs. Explain to them the benefits of
PALs and try engaging them in a dialogue
about their visual needs. A presbyope with
two pair of readers of different powers, one
for woodworking and another for reading,
might have never considered progressives.
This presbyope might have walked over to
the drugstore after his exam to buy more
readers. Through conversation, the benefits
of a progressive design might come to light,
resulting in a more sophisticated solution,
the PAL, not to mention less fumbling with
multiple pairs of readers.
EXPERIENCED PAL WEARER
This individual has worn progressives
before. Find out how they liked their last
pair of PALs. If they wore a hard design
with clear delineation and a confined view,
a new softer design PAL would be a nice
step forward. Or maybe they have already
used a newer, softer design. Did they have
only one pair? Could you help them with a
polarized pair of progressive sunglasses?
Do they find themselves doing activities for
a few hours at a time, like using the computer?
If so, an office PAL, also known as a
near-variable focus lens, would make a useful
second pair.

What about photochromics? Did you
explain to the patient that photochromics
are not a substitute for sunglasses, but
instead can be worn in a variety
of light conditions? How
about a UV treatment? Some
UV treatments turn lenses
yellow. A better solution
might be a high-index material
that filters UV, combined
with an AR treatment.

The experienced PAL wearer
may have no idea how many
lens options are available and
they may have no idea about
frame options. How about a
three-piece drilled mount? Is
your customer aware that their
new PALs could be a highindex
photochromic, AR pair,
in a modern three-piece drilled
mount?

Handled carefully and graciously,
experienced PAL wearers
give us an opportunity to
offer improvements and evolved
designs to the wearer.

MYOPES
A -2.00 myope is often in the
habit of taking their glasses off
to read, so the reading portion
of their PAL will not be its
strongest feature. The near portion of their
PAL may approach plano power. This
patient is used to seeing well up close, so
their PAL is only going to improve the distance.
PALs should be presented as an alternative
to glasses on and off for a mildly
myopic patient and not something to
improve vision at all distances, the way they
would for someone with a -5.00 and a 2.00
add. Clarifying expectations in the case of
a -2.00 myope prevents disappointment,
reduces remakes, and reduces frustration for
the dispenser.

HYPEROPES
Hyperopes may use their eyes a little differently
than myopes, who can frequently see
fine up close. Hyperopes may not have any
zone of comfortable vision without their
spectacles.

Some experienced opticians fit PALs a millimeter
high on hyperopes to get them into
the plus power sooner.
Select appropriate frames for myopes,
keeping in mind that round shapes can be
surfaced thinner than any other shape. Rectangular
frames, for example, mean this presbyope
gets a thicker PAL. When PALs have
plus in the distance power, they undergo the
prism thinning process, which helps reduce
thickness. It is equal in both lenses so no
imbalance is created.

EMMETROPES PALs providing correction for emmetropes
are going to help with intermediate and near
only, so it is necessary to find out if an all purpose
PAL is the right choice, worn all day, or
whether an office design is a better option,
supplying only intermediate and near correction,
and worn on an as-needed basis.

OFFICE DESIGNS
Using a computer with a general purpose
PAL can become uncomfortable after a few
hours because wearers find themselves holding
their head back a little to use the intermediate zone of the lens. A more specialized
lens emerged to fit this need, the office
design, a PAL made specifically for the distances
involved in working on a computer
and desk. Office PALs offer readers their full
reading prescription with a sizeable window
above it for intermediate use, for
keyboard and monitor viewing,
respectively.

Newer office PALs incorporate
softer designs and progressions
of power specific to particular
prescriptions. All PALs,
but most especially office
designs should be optimized
with AR treatments to further
reduce eyestrain associated
with computer monitor use
and to minimize glare from
overhead lighting.

Since office PALs typically
have no distance zone, they cannot
function as general purpose
PALs and are sold as second
pairs. Although some dispensers
might feel awkward suggesting
more than one pair of PALs for
the same presbyope, it should be remembered
that it would be appropriate for the
presbyope to have more than one pair of
shoes and even have some shoes more specialized
than others, such as a pair of loafers
and a pair of tennis shoes.

Office PALs are not computer-only spectacles.
They provide a solution whenever near
and intermediate distance correction is needed,
such as when playing the piano to see the
keyboard and music.

SHORT-CORRIDOR DESIGNS
Short-corridor designs were introduced in
the late ’90s as a way to deliver PAL performance
in a small or oval-style frame.
These PALs feature a corridor as small as
18mm and fitting heights ranging from
18mm to as low as 13mm, depending upon
the manufacturer’s design.

Although some early short-corridor
designs were merely squashed down versions
of conventional PALs, more recent
designs are specifically tailored to provide
enhanced PAL performance in small
frames, with digital designs being created in
short-corridor form. The biggest advance in
short-corridor designs has been the
improvement of the intermediate zone and
softening of the overall design.

The challenge for the ECP is to find a
short-corridor PAL that will allow patients to
choose from a full range of small frames,
while still providing plenty of reading area. A
good short-corridor PAL should offer excellent
reading vision even at low fitting heights,
soft design binocularity, low aberration and
reduced astigmatism.

Although good things can come in small
packages, it may be necessary to go bigger
for your presbyope to get all the benefits
from their PAL. For example, short-corridor
designs might be poor choices for headmovers,
but are excellent for experienced
PAL wearers.

DIGITALLY SURFACED PALS
The biggest advancement in PALs in
recent years has been the development of
digitally surfaced lenses. Optical labs can
now use special Rx calculation management
software to convert a progressive surface
design into a set of numbers called a
points file or cutting file. This
data can then direct a CNC
surface generator equipped
with a diamond cutting tool to
mill a lens design directly onto
a lens or mold surface. With
the right generator, software
and cutting file, labs can modify
the back surface of a semifinished
lens while cutting the
prescription curves, enabling it
to produce aspheres, atorics
and complex surfaces.

Digital technology is creating
new opportunities for ECPs
and wearers. Working with a
lab equipped with digital surfacing
technology, ECPs can
order PALs that are exactly
matched for each patient and
the frame they’ve selected.

MORE PALS, MORE OPTIONS
No one looks forward to becoming presbyopic.
In fact, some patients may dread the
prospect.

Yet it’s actually a great time to be a presbyope.
With so many progressive lens
options available today, there are visual and
cosmetic solutions for practically everyone.
All it takes for each patient to find the best
PAL for them is a knowledgeable and
experienced eyecare professional to open
their eyes to the possibilities.

Timothy Coronis is a certified optician who lives and works in Keene, N.H. He is also an American Board of Opticianry certified technical speaker. He can be reached at timothycoronis@hotmail.com.